Uncommon Coexistence of Eosinophilic Colitis, Asthma, and Elevated IgG4 Levels: A Case Report

Eosinophilic gastrointestinal diseases represent a rare and diverse group of conditions. Given that the pathogenesis of EoC is not well understood and is often linked to allergic conditions, this case underscores the necessity for further research into such unique presentations. The patient's prolonged gastrointestinal symptoms presented a significant diagnostic challenge, emphasizing the importance of ruling out various potential causes for elevated blood eosinophils. This exploration aims to enhance the understanding of such rare clinical scenarios and improve diagnostic accuracy in similar cases. We present a unique case of a 57-year-old patient with a medical history of asthma and allergic rhinitis who presented recurrent abdominal pain, significant blood eosinophilia, and elevated levels of Immunoglobulin G4. After ruling out hematological and secondary causes of eosinophilia, a biopsy of the colon mucosa revealed an excess of tissue eosinophils, confirming the diagnosis of EoC. The patient responded well to corticosteroids and was subsequently maintained on montelukast, with no recurrence of symptoms over 3 months. This rare confluence of EoC, asthma, and high levels of serum IgG4 in a single patient contributes to our understanding of these complex and interconnected disorders.